1. Field of the Invention
The present invention relates generally to the area of fluid current conveyors, and more particularly, to vertical tube section pivoting about an upper axis for use with a downsend pneumatic transport tube system.
2. Description of the Related Art
Pneumatic transport tube systems typically transport a carrier through a transport tube between two terminals. The carrier is moved by creating pneumatic pressure differentials within the transport tube with respect to the ends of the carrier. Pneumatic transport tube systems are often utilized by banks. A teller terminal, located in the bank, is connected by a pneumatic transport tube to a customer terminal located outside the bank such that a customer may use the customer terminal and is accessible to a user from a vehicle. Typically, the carrier in such systems is cylindrical and removable from the transport tube at the customer and teller terminals. The transport tube connecting the teller and customer terminals may be installed either overhead or underground. If an underground transport tube is utilized, the carrier moves up when it is received in the terminal and moves down when it is sent from the terminal. Consequently, a terminal for use with an underground transport tube system may also be referred to as an up-receive/down-send terminal or simply a downsend terminal.
The force available to move the carrier through the transport tube between the customer and the teller terminals is determined by the pneumatic pressure differential developed across the carrier. The maximum pressure differential is a design parameter and is determined by the size of the blowers and motors, etc. Consequently, every pneumatic transport tube system has a maximum pressure differential that may be applied across the carrier, and that maximum pressure differential determines the maximum load carrying capacity of the carrier.
With prior downsend terminals, the carrier is received in the terminal and moved to an exchange station at which point the carrier is out of the transport tube and within reach of the user. After finishing the transaction, the user typically inserts the carrier directly into a vertical section of the transport tube. The user may fill the carrier with a load that exceeds the maximum load carrying capacity of the carrier. However, there is no way to measure the load prior to the user inserting the carrier in the vertical tube section of the terminal. Consequently, if a carrier is overloaded, the carrier will drop to the bottom of the vertical tube section of the terminal and stop. The pneumatic forces developed in the transport tube will be insufficient to move the carrier through the transport tube. Therefore, the transport tube system is out of service until the overloaded carrier is manually removed. Downsend terminals, to which the user has direct access to the transport tube, have other disadvantages. For example, debris or other materials may be intentionally or inadvertently put into the vertical tube section.
Several downsend terminal constructions are known which do not provide the user of a customer terminal direct access to the vertical transport tube section. For example, in U.S. Pat. No. 3,976,264, a vertical tube section within the customer terminal pivots 90.degree. about a horizontal axis at the upper end of the tube section thereby moving the tube section from a vertical position to a horizontal position. The advantage of that construction is that the carrier may be moved between the vertical and horizontal orientations without requiring a 90.degree. elbow transport tube section, consequently a smaller terminal may be utilized. In another downsend terminal design disclosed in U.S. Pat. No. 3,985,316, after being received within the terminal, the carrier is deposited on a pallet which moves in a generally horizontal direction outward from the terminal toward the user. During the transaction, the user removes the carrier and then places it back on the pallet. The pallet then retracts back into the terminal, and the carrier is transported through the tube.
While those designs limit direct access of the user to the vertical tube section, those designs have the disadvantage of permitting an overloaded carrier to enter the vertical section of the transport tube system. Further, with those designs, debris and foreign matter may be pulled or carried to the top of a vertical tube section.